MATLAB: MatLab Automation Server Functions and Properties Feval(“load”, …)

com automationfevalvb code

I am having problems loading a Matlab workspace in VBA – the error I get is that the call to load cannot find "MatLab.mat" which makes no sense as I have provided the filename "reduce_to_common_factors.mat".
Here is my code down to the line which fails:
{Dim m_MatlabApp As Object
    Set m_MatlabApp = CreateObject("Matlab.Application")
    Dim wkbk As Workbook
    Dim wksht As Worksheet
    Dim ndim As Integer: ndim = 30
    Dim itsdim As Variant
    ReDim rho_matrix(1 To ndim, 1 To ndim) As Double
    ReDim output(1 To ndim, 1 To ndim) As Double
    ReDim my_output_real(1 To ndim, 1 To ndim) As Double, my_output_imag(1 To ndim, 1 To ndim) As Double
    Dim image() As Double, my_bool As Boolean, Result As String
    Set wkbk = Workbooks("Evaluate_LPI_Swap_30y_With_Smile.xlsx")
    Set wksht = wkbk.Worksheets("Modelling_LPI")
    Dim cnt_row As Integer, cnt_col As Integer, retVal As Variant
    wksht.Activate
    'Load the Excel correlation matrix into a double array
    For cnt_row = 1 To ndim
        For cnt_col = 1 To ndim
            rho_matrix(cnt_row, cnt_col) = wksht.Cells(5 + cnt_row, 4 + cnt_col).Value
            output(cnt_row, cnt_col) = 0
        Next cnt_col
    Next cnt_row
    'update the workspace variables in MatLab
    Result = m_MatlabApp.Execute("cd Q:\Team\Russell_Bickerton\MatLab\Data")
    retVal = m_MatlabApp.Feval("load", 0, "reduce_to_common_factors.mat")}
The help topic for this function call is MatLAB, Functions, External Interfaces, MATLAB COM Automation Server Support, MatLAB Automation Server Functions and Properties.

Best Answer

Hi,
with respect to the IDL signature:
HRESULT Feval([in] BSTR functionname, [in] long nargout, 
[out] VARIANT* result, [in, optional] VARIANT arg1, arg2, ...)
I guess this
m_MatlabApp.Feval("load", 0, "reduce_to_common_factors.mat")}
needs to be
 m_MatlabApp.Feval("load", 0, Nothing, "reduce_to_common_factors.mat")}
Or maybe instead of Nothing use vbNull. Not sure what you need exactly.
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